Ga-68 DOTA-NOC PET/CT for the Detection of Residual/Recurrence in a Rare Case of Sacral Spinal Canal Paraganglioma

Thoracic Extradural Paraganglioma Localized on 68Ga-DOTANOC PET/CT

ABSTRACT

We present the case of a 33-year-old woman with complaints of headache and palpitations with raised urinary catecholamines. Ultrasound of the abdomen was noncontributory, and the patient was referred for 68Ga-DOTANOC PET/CT, which revealed tracer accumulation in the thecal sac/spinal canal at D5-D7 level, suggestive of a thoracic paraganglioma. MRI of the spine subsequently confirmed the presence of an extradural mass in the spinal canal extending from D4 to D8.

68Ga-DOTANOC PET/CT in an Atypical Extraskeletal Paravertebral Hemangioma Mimicking as Neurogenic Tumor in a Known Case of Breast Cancer

Ga-DOTANOC PET/CT is well documented in evaluation of well-differentiated neuroendocrine tumors and in other lesions with somatostatin receptor expression such as pheochromocytoma, paraganglioma, neuroblastoma, meningioma, and mesenchymal tumors causing oncogenic osteomalacia. Causes of interpretative pitfalls include prominent pancreatic uncinate process activity, inflammation, osteoblastic activity (degenerative bone disease/fracture/vertebral hemangioma), splenunculi/splenosis, and others. We present a case of extraskeletal paravertebral lesion detected in a known case of breast cancer with increased Ga-DOTANOC uptake later proved to be hemangioma. This is a novel finding and should be kept as a rare benign differential in evaluation of lesions with somatostatin receptor expression.

Leptomeningeal dissemination of a low-grade lumbar paraganglioma: case report

Leptomeningeal dissemination of paraganglioma is rare, with only 2 prior cases in the literature. The authors present the case of a metastatic low-grade lumbar paraganglioma via leptomeningeal dissemination. This report emphasizes the utility of 3,4-dihydroxy-6-¹⁸F-fluoro-l-phenylalanine (¹⁸F-FDOPA) PET scanning for diagnosis, as well as the combination of radiation therapy and alkylating chemotherapeutic agents for the treatment of this rare phenomenon. The patient was a 61-year-old woman who presented with low-back pain and was found to have an isolated L-3 intrathecal tumor on MRI. Sixteen months after gross-total en bloc resection of the paraganglioma, the patient again became symptomatic with new neurological symptoms. MRI findings revealed enhancing leptomeningeal nodules throughout the spine. ¹⁸F-FDOPA PET/CT scanning was used to confirm the diagnosis of disseminated paraganglioma. Intrathecal thiotepa, radiation therapy, and systemic therapy with capecitabine and temozolomide have been used sequentially over a 2-year period, with each able to stabilize tumor growth for several months. The authors also summarize the 2 other reports of leptomeningeal dissemination of paragangliomas in the literature and compare the course and management of the 3 cases.